1. Field
Apparatuses consistent with exemplary embodiments relate to a surveillance system, and more particularly, to a surveillance system in which network cameras and a server are interconnected via a communication network.
2. Description of the Related Art
In a surveillance system in the related art, network cameras and a server are interconnected via a communication network.
In such a surveillance system, compressed video data from network cameras is transmitted to a server and subscribers via a communication network. Hereinafter, the term “subscribers” refers to personal computers (PCs) or wireless terminals, such as smart phones, of subscribed users.
In the surveillance system, since compressed video data from a plurality of network cameras is simultaneously transmitted to the server and the subscribers, a massive amount of video data is transmitted via the communication network. For example, if it is necessary to transmit compressed video data from an arbitrary network camera at a transmission rate of several megabits per second (Mbps), a transmission rate of dozens of Mbps is required for 10 network cameras to transmit compressed video data. The transmission rate increases when a large number of network cameras are required or high-quality video is required.
Therefore, a surveillance system in the related art has the problems below due to transmission of a massive amount of data.
First, communication errors frequently occur during transmission of video data, and thus, the reliability of a surveillance function is low.
Second, a massive amount of video data from a plurality of channels is stored in a server, e.g., a network video recorder (NVR), and thus, a relatively long time is required to search for video of a particular channel or interest according to a user request.
Third, due to the first and second problems, that is, the low reliability of a surveillance function and a relatively long time for searching for video, it is difficult to provide various services related to a surveillance function to subscribers.